Britain’s Nuclear Subservience

In a brief exchange during Prime Minister’s Questions last month, the leader of the Liberal Democrats, Ed Davey, asked Keir Starmer about Trident replacement. ‘We have to make a choice now,’ Davey said: ‘lease new missiles from the United States, accepting whatever terms the president gives us, or build our own here in the United Kingdom.’ The prime minister replied that Davey was ‘advocating a plan without knowing how much it would cost and how it would work’. The discussion moved on.

Both men spoke of Britain’s ‘independent nuclear deterrent’. But the UK’s nuclear weapons capability is dependent on the US. Not only does Britain rent its Trident missiles from America, but the British-built warhead designed to be carried by those missiles, the Holbrook, is closely based on the American W76. The Los Alamos National Laboratory announced last year that a replacement for the W76 is going ahead: the W93 should be ready by 2034.

There is no need for the UK to replace its warheads. A Holbrook’s maximum yield is ninety kilotons of TNT-equivalent, about six times the size of the bomb dropped on Hiroshima. But the US Navy wants a new warhead in the mid-2030s and the UK has to follow suit even though there are no good reasons to do so. No one in Britain played any part in choosing the parameters of the W93.

George Robertson, the former Labour minister of defence and Nato secretary-general who now works for the Cohen Group, has said that the UK’s military dependence on the US is ‘no longer tenable’.

Britain’s nuclear subservience to the US dates from the 1958 Mutual Defence Agreement (MDA) between Washington and London:

Each party will exchange with the other party other classified information concerning atomic weapons when, after consultation with the other party, the communicating party determines that the communication of such information is necessary to improve the recipient’s atomic weapon design, development and fabrication capability.

The minutes of the first meeting of nuclear scientists from both sides in 1958, which seem to have been declassified by the US by mistake, show that the US provided ‘details of size, weight, shape, yield, amount of special nuclear material’. Several weapons were described. Britain’s nuclear bombs have been built at Aldermaston to an American design ever since.

President Kennedy and Harold Macmillan met at Nassau in the Bahamas in 1962 and agreed that the UK could use American Polaris missiles in its submarines. Charles de Gaulle was offered the same deal but declined. He said that the US could not be trusted and insisted that France had to take nuclear decisions for itself. British nuclear warheads are all carried by US-dependent submarine-launched ballistic missiles (SLBM). France builds its own SLBMs and its own warheads.

David Manning was Britain’s ambassador to Washington from 2003 to 2007. ‘It is very difficult to imagine,’ he told the International Relations and Defence Committee last year, ‘what we will do to defend ourselves if, for example – this is very hypothetical – the Trump Administration decide that they will end our nuclear co‑operation deal, or Trump moves out of Nato, or even becomes just so equivocal about Nato that the Article 5 guarantee is no longer plausible.’

Trump and his war on Iran have given new urgency to Anglo-French nuclear co-operation, which should replace the ‘special nuclear relationship’ with the US before Britain needlessly commits itself to the US-dependent modernisation of its nuclear weapon system. If Britain were to join France, its first action should be to extract itself from its agreement to buy the W93 from the US. Aldermaston can make its own warheads or make them to a French rather than a US design.

The Nuclear Non-Proliferation Treaty (NPT) was drafted by the UK and US to forbid weapon-state signatories from helping non-weapon states to develop nuclear weapons. But they are not forbidden from helping one another: the MDA and Polaris Treaties between the UK and US are not affected by the NPT. A similar agreement between the UK and France would also be allowed by the treaty. France delivers its weapons on SLBMs, cruise missiles and aircraft and could share information with Britain in these fields (as it already does in some of them).

In any case the NPT may well be obsolete. India, Pakistan, Israel and North Korea all have nuclear weapons. Faced with a hostile Russia, it might be sensible for Germany and Poland to have them too. It certainly makes sense for the UK to decouple its nuclear weapons programme from the US.